Air test suggests life possible on Mars
CNN

A strange and hardy terrestrial microorganism can grow in atmospheric and soil conditions that in some ways resemble those on Mars, suggesting that life could thrive on the red planet, according to scientists. The creatures, known as methanogens, survived in a thin atmosphere of hydrogen and carbon dioxide and in a special brew of volcanic ash altered to simulate the properties of martian soil, including its density, grain size and magnetic properties. The results, in addition to the presence of vast stores of underground water on Mars, lend support to the theory that the planet once hosted or now hosts life, said Tim Kral, a researcher at the University of Arkansas in Fayetteville.